Which of the following statements is true ?

Options

A. `HNO_(3)` is a stronger acid than `HNO_(2)` ,
B. `H_(3)PO_(3)` is stronger acid than `H_(2)SO_(3)`
C. In aqueous solution HF is stronger acid than HCI
D. `CHIO_(4)` is a weaker acid than `HCIO_(3)`

Answer

To determine which of the statements is true, we will analyze each statement one by one.

### Step 1: Analyze Statement 1
**Statement:** HNO3 is a stronger acid than HNO2.

**Analysis:**
- HNO3 (Nitric acid) is a strong acid, while HNO2 (Nitrous acid) is a weak acid.
- The reason for this is that the conjugate base of HNO3 (NO3-) is resonance stabilized, meaning it can distribute the negative charge over multiple atoms, making it more stable.
- In contrast, the conjugate base of HNO2 (NO2-) does not have the same level of resonance stabilization.
- Therefore, HNO3 is indeed a stronger acid than HNO2.

### Step 2: Analyze Statement 2
**Statement:** H3PO3 is a stronger acid than H2SO3.

**Analysis:**
- H3PO3 (Phosphorous acid) and H2SO3 (Sulfurous acid) are both weak acids, but H2SO3 is generally considered to be a stronger acid than H3PO3.
- This is due to the electronegativity of sulfur being higher than that of phosphorus, which stabilizes the conjugate base of H2SO3 more effectively than that of H3PO3.
- Thus, this statement is false.

### Step 3: Analyze Statement 3
**Statement:** In aqueous solution, HF is a stronger acid than HCl.

**Analysis:**
- HF (Hydrofluoric acid) is actually a weaker acid than HCl (Hydrochloric acid).
- HCl is a strong acid that completely dissociates in water, while HF does not dissociate completely due to the strong hydrogen-fluorine bond.
- Therefore, this statement is also false.

### Step 4: Analyze Statement 4
**Statement:** CSIO4 is a weaker acid than HCIO3.

**Analysis:**
- CSIO4 (Chlorosilicic acid) is not a commonly referenced acid, but HCIO3 (Chloric acid) is a strong acid.
- Generally, without specific data on CSIO4, we can assume that HCIO3 is a stronger acid than CSIO4 based on its known properties.
- Thus, this statement is likely false.

### Conclusion
After analyzing all four statements, we conclude that the first statement is true: **HNO3 is a stronger acid than HNO2.**